TEHRAN, Jan. 19 (Xinhua) -- An official of Iran's intelligence ministry counter-espionage said on Monday that Iran had discovered and dismantled a "soft overthrow" project, the official IRNA news agency reported.

The official, who was not named, said that his country had discovered and arrested four members of the network involved in "soft overthrow" projects against the country.

Among the detainees, there were two brothers named Arash and Kamiar Alaei, the semi-official Fars news agency reported.

The two brothers, who were also doctors and practitioners in HIV/AIDS in Iran, had been in jail since June, 2008.

Claiming that the United States was at the back of the project, he said that "the U.S. was trying to implement one of its old strategies practiced against the former Soviet Union, known as 'Riga' project, in Iran as well, which was re-activated in Dubai, lately," in an attempt to penetrate into the country's civil institutions.

Iran's judiciary spokesman Ali Reza Jamshidi said on Saturday that Tehran's Revolutionary Court convicted and sentenced four Iranians to jail on charges of trying to topple the Islamic government with the support of the U.S. State Department and the CIA, IRNA said but did not elaborate on the length of the sentences.

Jamshidi said the four were detained and tried in Tehran. He said they planned to recruit others to be trained abroad for anti-Iranian activities.

Iran has incessantly accused the United States and Israel of plotting against the Islamic regime by disclosing documents and trying their alleged agents in the country.

In November 2008, Major General Mohammad Ali Jafari, Commander of the Islamic Revolutionary Guard Corps (IRGC), said that Iran had discovered an Israeli spy network.

Iran also hanged in Tehran on Nov. 17 an Iranian citizen named Ali Ashtari, charged of spying for Israel, to show that it had entered a "serious intelligence war with" Israel.

Meanwhile, an Iranian Intelligence Ministry official warned Saturday that Iranians should be on alert "about the serious danger of penetration of the Israeli intelligence services to Iran's internet and telecommunications network."